1. Field of the Invention
The present invention relates to a method, system, and program for replicating a file.
2. Description of the Related Art
File replication involves maintaining a copy (replica) of a file on a remote storage that may be updated locally. Any local updates applied to the file subject to replication are copied over (replicated) to the remote storage. For instance, the International Business Machines (“IBM”®) Tivoli® Storage Manager product provides software for a client and server systems so that the client system backs-up only a changed portion of a file on the server, either on byte level or on block level, instead of transferring the whole file to the server every time. (IBM and Tivoli are registered trademarks of IBM) The changed file portion is backed up as a differential backup relative to the last complete backup of the file (base or reference file) and it is called delta file. All changes since the last complete backup of the file are included in this delta file. In the case of a restore, software provides for the restore of the whole file by restoring only two sub-file components, one delta file and the last complete backup of the whole file, the base file.
The IBM Tivoli Storage Manager requires that the replication operations are implemented in software programs that run on both the client and the server storage receiving the delta files. Thus, proprietary agent software is implemented in both the endpoints, client and server machines, to exchange information and messages as part of the replication process.